The present invention relates to a pinch roller actuator for a tape recorder, and more particularly to a pinch roller actuator for use in small-sized tape recordes such as cassette tape recorders equipped with radio receivers.
Tape feed mechanisms of tape recorders include a capstan and a pinch roller as principal parts. In the recording and playback modes of operation, the magnetic tape is pressed against the capstan by the pinch roller so as to be fed at a constant speed. In the rewinding and fast forward modes of operation, the tape is fed only by one of the reels with the pinch roller disengaged from the capstan to release the tape from contact with the capstan.
The pinch roller is movable into and out of contact with the capstan by an actuator operable in response to the changeover between tape feeding modes. The known actuator comprises as a drive source a plunger or a link mechanism movable in response to tape feed mode changeover. The actuator is actuated by a drive force which must be applied throughout a mode changeover operation when the pinch roller is brought into contact with the capstan. With the plunger-type actuator, a large-size plunger having a relatively large stroke is required. Where the link mechanism is employed, the manual mode changeover operation will be effected with an increased force unless the leverage is large, and if the leverage is large, then the link mechanism becomes large in size. Therefore, the known actuator mechanisms are relatively large in size and hence cannot be incorporated into small-size tape recorders.